Rotary-disk eccentric bit



Aug. 21, 192s.

s. G. WOODRUFF ROTARY DISK ECCENTRIC BIT Filed JulyljiZS Z l ,W www 55 MW Patented Aug. 21,1928.

siIELnnY e. WOODRUFF, or INGLEWooD, 'CALIFORNIA ROTARY-Disiz iidcnivm'nic izrr.

Application led July 1,; 1925. Serial No. 40,857.

This invention relates to improvements in rotary disk bits used in well drilling operations and the like. s i

An object of the in vention is providean improved type of rotary disk bit, in which the rotary disk Vcutters are sliiftable orare capable'of rotating upon axes, the positions of' which may be varied or adjusted.

Another object of the invention is to provide a rotary disk bit having disk cutters rotatable about movable axes, which will permit the cutters to be` lowered through a casing, and upon encountering the bottom of a i eters.

well hole to expand, so that a holemay be drilled which is larger'than the'exterioi' diameter of the casing.

A further lobject of the invention is to provide a rotary disk bit in which the rotary disk cutters are adjustable, so that the bit may be caused to drill holes ofvarious diam- With` thev u foregoing and other objects in view which will be made manifest in the following detailed description and specifically pointed out inthe appended claims, refer 4,ence is had to the accompanying drawings for an illustrative embodiment, of the invention, wherein Fi ure 1 is a side elevation of the improved bit, t sition, Y

Fig'. 2 is anend elevation of the same, Fig. 3 is a vertical section taken on the line 3 3 of rig. 1,'

Fig. 4 is a side elevation. of the bit, the cutters being shown in expanded position, and

Fig, 51s a side elevation of a slightly modified form of construction. Referring to the accompanying drawings wherein similar refer nce characters designate similar parts thr ughout, the improved bit consists of a body 10 having .its upper end threaded, as atll, for attachment to a drill tube. A vertical axial bore 12 is forme-d in they body 10, permitting circulation yfluid to be discharged therethrough onto the cutters.

Arms 13 and 14 depend from theL body 10, and

" and are rotatable -thereiin These pins orA these arms are parallel 'and are arranged directly opposite each other; Pins ory bolts 15 and 16 extend through the arms 13 and 14 bolts are shown as provided with heads 17 which are received in the arms 13 and 14, and

with screws or threaded shanks 18. Eccentrics 19 and 20 are threaded onto the threaded Shanks 18 and are tightened against the e cutters being shown ip retracted po bodies ofthe pins or bolts 15 and"16 respectively. Each of the eccentrics is provided (with a peripheral shoulder or flange 21, which serves to maintain the disk cutters 22 and 23 upon their respective eccentrics 19 and 2O by permitting the disks to rotate on the eccentrics.

In themodiication shown in Figs. 1 to 4 inclusive the eccentrics 19 and 20 carry pins 24, which slidably engage upon the lower ends of the arms 13 and 14. These pins areen, gageable upon stops 25Aformedonl the arms, so that the rotational movement of'the eccentrics is limited.

By the improved construction it will be readily-appreciated that as the bit is lowered into a hole, it may readily pass through the casing in the collapsed position shown in Fi 1, in which the-axes of the cutters are near y in alignment. As the `cutters engage the bottom of the hole,they will causethe eccentrics f and the pins or boltsv 15 and 16 to turn, so

thatthe cutters will then assume the position shown in' Fig. 4, which is the expanded position of the bit. It will be readily appreciated that upon-rotation of thebit, the cutters,

While in this posit-ion, will cut a hole of larger diameter Vthan the diameter of the casing, through which the bit has passed. When it is necessary to pull the .bit from the hole, the

upward movement will allow the eccentrics to return to the position shown in Fig. l, per- 'mitting the bit to be withdrawn throufh the gageable upon the pins 24 for limiting the movement of 'the eccentrics.

Inthe modification shown in Fig. 5, a series of apertures26 is formed in each of the arms, and pins 27 are insertable-in either of the apertures and are engageable upon the eccentrics. By this construction the rotary disks 22 and 23 can be caused to be maintained in 'the fully'collapsed position or in expanded position or in a position therebetween. In this manner the bit may be caused to drill holes of various diameters, depending upon which hole 26 the pin 27` is positioned in.

A somewhat unobvious advantage of the improved construction, employing the eccentries, resides in the fact that this permits the depending arms 13 and 14 to be positioned los from cutters heretofore employed, in which 4the arms 13'and 14 are somewhat oiset with respect to each other, Although the arms 13 -in the detail of construction may be made without departing from the spirit or scop'e of and 14 are directly opposite, the pins or bolts 15 and 16 pass through their centers, and at the same `time the disks rotate jupon axes which are located other than through the centers of the arms 13 and 14. Because of the fact that the arms are directly opposite, instead of offset, the space within the hole occupied by the bod of the bit during rotation is smaller than in its having the offset arms.

It will be understood that various changes said arms, eccentrics secured to said members, dlsk cutters rotatable upon said eccentrics,

and means permitting but limiting rotational movement of said members upon said arms, whereby the bit may be lowered linto a well hole with the cutters in contracted positions, and upon encountering the bottom of the hole they may move into expanded positions.

' 3.' A rotary disk bitcomprising a body having a pair of spaced depending arms and a vertical bore a apted to discharge circulation Huid centrally of the space between said arms, members rotatably mounted upon said toiff having a pair of depending spaced arms, eccentrics rotatably mounted upon the bit adjacent the inner opposed faces of thearms, and disk cut-ters rotatableupon the eccentrics, the space between the cutters being unobstructed. l

6. A rotary drill bit comprising a body havnga pair of depending spaced arms, eccentrics rotatably mounted upon the bit adjacent the inner opposed faces of the arms, disk cutters rotatable upon the eccentrics, and means connecting each `eccentric to the arm on which it is rotatable for preventing rotation of the eccentric in at least one direction.

7.` A rotary drill bit having a pair'of depending spaced arms, pins extending through the arms, eenentrics which .are detachable from the pins mounted thereon adjacent the arms, said eccentrics being rotatable relative- `ly to the arms, means limiting the rotational movement of the eccentrics, and diskA cutters rotatable upon said eccentrics. l 8. A rotary drillbit comprising a body having a pair of depending spaced arms, ec'

centrics rotatably mounted upon the bit adjacent the inner opposed faces lof the` arms and disk cutters rotatable upon the eccentrics, the space -between the cutters being unobstructed, one side of each cutter bearing against the inner face of its respective arm.

9. A rotary drillbit Icomprising a body having a pair of dependin spaced arms, ec-

lcentrics rotatably mounte Vupon the bit adjacent tlie inner opposed faces of the arms, disk cutters rotatable upon the `eccentrics, and

arms, flanged eccentricsthreaded onto saidimeans connecting each eccentric to the' arm posed faces of said arms, disk cutters rotaty ably mounted upon said eccentrics, and means permitting but limiting the rotational movement ofsaid members as and for the purpose described.

5. -A rotary drill bit comprising a body on which it is rotatable for limiting rotation of the eccentric in atleast one direction', each cutter having one side bearingagainst the inner face of its respective arm.

1,0. A rotary drill bit Vcomprising a body having a pair of depending spaced arms, disk cutters rotatably mounted upon the inner opposed faces of the arms, the space between the cuttersbeing unobstructed, each cutter having oneside bearing against the inner face of its respective arm, and means permitL ting .movement of the axis of rotation of the cutters relatively to the arms.

In vtestimony whereof yI have signed my name to this specification. I

` SHELLEY G. WC)ODRUF. 

